Chuck for bit braces



Nov. 11, 1924. 1,515,272

T. PRENTICE CHUCK FOR BIT BRAGES Filed Nv. 27, 1922 Patented Non. il., i924..

ir stre rara THOMAS IPRENTICE, OF SOTHINGTON, GONNECTZCT, ASSGNOR TO THE PEOR, STOV & WTLCOX COMPANY, OF SOUTHINGTON, CONNECTOUT, A CORPORATION.

CHUCK FOR BIT IBB/ACES.

Application filed November 27, 1922.

To all whom t may concern:

Be it known that I, THOMAS PRnNTicn, a citizen of the United States, residing at Southington, in the county of Hart-ford and State of Connecticut, have invented a new and useful Improvement in Chucks torl Bit Braces; and do. hereby declare the following, when taken in connection with the accompanying drawings and the characters of reference marked thereon, to be a full, clear, and exact description of the same, and which said drawings constitute part of this application, and represent, in-

Fig. 1 a View in side elevation of a bitbrace provided with my improved chuck.

F ig. 2 an enlarged View of the chuck in central longitudinal section, with the jaws shown partly open.

Fig. 3 a broken detail view, showing the removable safety-collar as engaged with an abutment of the shank for limiting the outward movement of the threaded operatingsleeve of the chuck.

Fig. 4L a detached plan view of the removable safety-collar.

Fig. 5 an edge view thereof.

My invention relates to an improvement in chucks for bit-braces, the object being to produce a simple, convenient and effective chuck constructed with particular reference to providing strong, convenient, attractive and effective means for limiting the outward movement of its threaded operating-sleeve, such means reducing the shock and wear of stopping the sleeve to the minimum.

In carrying out my invention, as herein shown, I employ a removable safety-collar 10 having its periphery milled, or otherwise roughened, and formed with an externallythreaded annular flange 11 adapted in diameter to be screwed into the inner end of the rotary operating-sleeve 12 of my improved chuck, the said sleeve being thereto furnished, just within its inner end, with retaining screw-tln-ends l?) of [ine pitch, in addition to its heavy, internal operating threads 14, which extend nearly throughout its length. The said collar 10 substantially corresponds in diameter to the external diameter of the operating-sleeve 12, and, therefore, does not interfere with the convenient and comfortable grasping of the same for the operation thereof, and also presents a workmanlike and attractive appearance. The said sleeve is applied to a crank-type bit-brace of any Seriai No. 603,524.

approved construction,v needing no detailed description, herein generally' designated by the numeral 15, and furnished with a shank lo, corresponding ink dian'ieter to the internal diameter of the safety-collar 10 and its fiange 11, and provided at its outer end with outstanding' enternai threads 17, co-acting with the threads 145 of the sleeve 12, the bottoms of the said threads 17 being co-incident with the periphery of the shank proper, so that the full diameter of the threaded outer portion of the shank :recede the diameter of the unthreaded inner portion thereof, or the shank may be viewed as reduced in diameter at a point adjacent to its threaded portion. The said' shank is formed with a diai'netrical slot 18 intersecting its threaded portion approximately throughout the length thereof, and receiving suitable coinpleinentary chuck-jaws 19, opened by the action of-a spring 20 and closed by a cone 21 carried by a cap 22, the inner end of which is internally threaded for being screwed over an externally-threaded, integral, annular shoulder 23 formed upon the extreme outer end of the operating-sleeve 12. The said cap and sleeve, as thus combined, act as oneV piece,fwhen the chuck is assembled, in controlling the jaws, and are respectively recessed to form a raceway 24 for a group of balls 25, which reduce to the minimum the friction between the cone and the cap when the cap is turned with the sleeve 12 for closing the jaws. The said safety-collar `is made removable to permit the sleeve to be demounted as required for replacing the jaws, or for any other purpose which requires access to the interior of the chuck.

For the Opening and closing of the jaws 19 by the action, on the one hand, of the spring 2O and, on the other hand, of the cone 21, the sleeve and shank are relatively rotated in the usual manner for their relative longitudinal movement. In opening the jaws, the sleeve moves outward with respect to the shank, and when the jaws are fully opened, the flange 11 of the safety-collar 10, mounted as described in the inner end of the sleeve, engages with the inner coil of the threads 17 upon the shank, as shown in Fig. 3, and limits the outward movement of the sleeve, whereby the user is informed by the shock of thisengagement that the jaws have been brought into their full open positiefs Without the necessity el: reversing; the b e ace and eX- amining the chuck to ascertain the precise position et the jaws. rlhe stopping of the sleeve in the manner described also prevents it from being` demounted from the shank by having its threads le run out of engagement with the threads la thereof, and thus necessitate the re-engagement et the said threads for re-rnouiltin` the sleeve upon the shank. The surfaces lgironght into play are so large that no matter how rapidly the operated, the shock et the brace is bein!" sudden engagement of the collar with the inner coil oi the threads l? et the shank will result in no damage or jamming, and the wear is so distributed as to be negligible. The safety-Collar also ,novides a neat and attractive finish for the inner end oit the sleeve and excludes all dust and chips therefrom.

l claim:

l. is a new article ot manufacture, a bitw brace having ai crank, a shank having integral, external threads et larger diameter posed periphery milled and provided with an externally-tlireaded flange, the threads et which are engaged with the said threads et iine pitch located Within the inner end of the sleeve and the end ot which engages with the helical outer convolution ot the thread of coarse pitch upon the shank, whereby the outward helical movement of the sleeve upon the shank is electively checked without resulting wedging action.

As a new article or manufacture, a crank-type bit-brace having crank, a

shank termed 'with ollstanding threads and with a jaw-receiv1ng slot intersecting the saine, a jaw-operating sleeve having internal three l; internieshing with the o'tfstanding threads et the shank, jaws located in the said slet i'or operation by the said sleeve, and a removable stop-collar of tivo diameters, or which its larger diameter corresponds to the external diameter of the sleeve, and oi: which the smaller diameter is externally threaded for being screwed into internal threads 'terrified in the inner end oit the sleeve and adapted to co-act directly wit the outer convolution of the offstanding threads upon the shank for stopping` the sleeve from being demounted When the crank is reversed, the larger and smaller diameters oit the said stop-collar being diferentiated by the thickness of the said sleeve.

ln testimony whereof, l have signed this speeitieation in the presence, ot tivo subscribing;l Witnesses.

THOMAS PRENTCE.

lllitnesses L l). BLOB, "i PETER HULTON, 2nd. 

